1. Heat load at the ILC positron target and collimator system
O. S. Adeyemi1, V. Kovalenko1, G. Moortgat-Pick1;2
L. Malysheva1, S. Riemann2, F. Staufenbiel2, A. Ushakov1
1University of Hamburg
2DESY
- methods for positron production
- temperature simulations in a photon collimator system
- temperature simulations in the ILC positron target region
- conclusion
F.Staufenbiel / / 2.LC Forum

2. what we want to have ! 2*1010 e+ /bunch at IP
polarised positron production
what we want to have !
2*1010 e+ /bunch at IP
2625 bunch /train (0.97ms)
5 train /s
photon source
e+ polarisation possible
conventional source
no e+ polarisation!
F.Staufenbiel / / 2.LC Forum

3. what we want to have ! 2*1010 e+ /bunch at IP
polarised positron production
what we want to have !
2*1010 e+ /bunch at IP
2625 bunch /train (0.97ms)
5 train /s
F.Staufenbiel / / 2.LC Forum

4. collimator polarised positron production Pe+ Yield [e+/e-]
no collimator
27 %
4.4 (100%)
2 mm
35 %
4.0 (91%)
1.4 mm
47 %
3.2 (73%)
1.0 mm
60 %
2.2 (50%)
F.Staufenbiel / / 2.LC Forum

5. 250 GeV e- modelling the ILC-target unit
2*1010 e- / bunch = 3.2 nC / bunch
2625 bunch / train (0.97ms) = MHz repetition rate
5 train / s
-> 4.6*1015 photon / train
Titan target for polarised positron production r
~ 14.4 MeV e+
250 GeV e-
~ 28.8 MeV photon beam
distribution of
heat load !!
helical undulator
r = 1 m
vrim = 100 m/s
( 955 rpm = 15.9Hz )
F.Staufenbiel / / 2.LC Forum

6. modelling the ILC-target unit
flux concentrator
beam pipe
vacuum seal
bearing
motor
chamber
~ 28.8 MeV photon beam
d1 = 1.0 cm , l1 = 5.0 cm
d2 = 5.0 cm , l2 = 3.0 cm
d3 = 8.0 cm , l3 = 12.5 cm
F.Staufenbiel / / 2.LC Forum

7. ~ C W this is to much !! TW = 1800 K / train D Q m cv
flux concentrator
beam pipe
vacuum seal
bearing
motor
chamber
collimator
~ 28.8 MeV photon beam
r = 0.1 cm -> _____ K / train
14 000
???
this is to much !!
F.Staufenbiel / / 2.LC Forum

8. but this is still to much !!
C Ti W
modelling the collimator
r = 0.1 cm
D TTi K / train ~
D TW K / train
D TC K / train
but this is still to much !!
F.Staufenbiel / / 2.LC Forum

9. C Ti Fe W C Ti W C Ti Fe W modelling the collimator r = 0.1 cm
z = 1.2 m
D TTi K / train ~
D TFe K / train
D TW K / train
D TC K / train
-> 40 K / train
-> 20 K / train
D TW K / train ~
F.Staufenbiel / / 2.LC Forum

10. C Ti modelling the collimator r = 0.1 cm z = 1.2 m D TC 500 K / train
D TTi K / train ~
D TFe K / train
D TW K / train
D TC K / train
-> 200 K / train
z = 4.0 m
-> 40 K / train
-> 20 K / train
F.Staufenbiel / / 2.LC Forum

11. C Ti Fe W modelling the collimator l = r – r0 . lC A DT QC = l . 300K
r = 0.1 cm
z = 1.2 m
D TTi K / train ~
D TFe K / train
D TW K / train
D TC K / train
-> 200 K / train
-> 40 K / train
-> 20 K / train
QC =
lC A DT l .
l : heat conduction coefficient [W/m/K]
Azyl : mean girthed area of the collimator [m2]
l : heat conduction path length [m]
DT : difference in temperature [K]
Q : heat current .
F.Staufenbiel / / 2.LC Forum

12. lC 2p ( r-r0 ) z DT = ln( r / r0 ) modelling the collimator . .
z = 1.0 cm
r = 0.1 cm
QC =
lC A DT l .
lC 2p ( r-r0 ) z DT
ln( r / r0 )
zyl. =
l : heat conduction coefficient [W/m/K]
Azyl : mean girthed area of the collimator [m2]
l : heat conduction path length [m]
DT : difference in temperature [K]
Q : heat current .
F.Staufenbiel / / 2.LC Forum

13. a b c d modelling the flux concentrator 2.0 cm m b s
d1 = 1.0 cm , l1 = 5.0 cm
d2 = 5.0 cm , l2 = 3.0 cm
d3 = 8.0 cm , l3 = 12.5 cm
F.Staufenbiel / / 2.LC Forum

14. ~ - QTi target 6 kW / train ~ 130 K / train | 2.0 cm POSITRON beam
vrim = 100 m/s
-> 50 pulses hits in
the same position
1.5 cm
tungsten collimator
for flux concentrator
F.Staufenbiel / / 2.LC Forum

15. ~ ~ ~ ~ - QTi target 6 kW / train - QW colli 115 kW / train -
~ 50 K / train |
~ 80 K / train |
~ 320 K / train |
flux concentrator ~
6 kW / train
QTi target - ~
115 kW / train
QW colli - ~
20 kW / train
Qflux con+W -
tungsten collimator
for flux concentrator ~
100 kW / train
Qflux con-W -
F.Staufenbiel / / 2.LC Forum

16. Conclusion C Ti Fe W C Ti C Ti W C Ti Fe W ->
- heat loads (temperatures) for different collimator designs are simulated
-> transfered in manageable regions
C Ti Fe W
C Ti
C Ti W
C Ti Fe W
->
- heat load in the target and flux concentrator are simulated
temperature
power
target
80 K/train
6 kW/train
flux concentrator - Wcolli
115 kW/train
flux concentrator + Wcolli
50 K/train
20 kW/train
Wcollimator
320 K/train
100 kW/train
F.Staufenbiel / / 2.LC Forum

17. Conclusion
- heat loads (temperatures) for different collimator designs are simulated
-> transfered in manageable regions
- heat load in the target and flux concentrator are simulated
temperature
power
target
80 K/train
6 kW/train
flux concentrator - Wcolli
115 kW/train
flux concentrator + Wcolli
50 K/train
20 kW/train
Wcollimator
320 K/train
100 kW/train
- what is now to do ?
-> heat evolution studies in the single components + induced mechanical
stress due to heat evolution facilitate by ANSYS simulation software
F.Staufenbiel / / 2.LC Forum